The objectives of this project are to identify and describe environmental and host determinants of cancer in areas of the U.S. at high risk of cancer through the use of analytical epidemiologic techniques, particularly case-control studies of specific cancers. Completed during the year were interview studies of (a) breast cancer in Alberta, Canada, which revealed higher risks among women with diets high in intake of beef and pork, and found that patterns for other risk factors often differed between pre- and post-menopausal women; (b) oral cancer among women in North Carolina, which did not confirm a previously reported link to textile manufacturing, but showed an association with mouthwash use limited to abstainers from tobacco and alcohol; (c) lung cancer in Pennsylvania, which found increased risks among long-term steel workers, suggesting that previous estimates of lung cancer among workers may have been underestimated; and (d) renal pelvis cancer in Minnesota showing a strong, causal association with cigarette smoking.